Cup washer



L. E. LA BRIE Jan. 18, 1949.

CUP WASHER Filed Aug. 27, 1945 INVENTOR. l 006:: 98m:

armed If washer is made shall be soft enough to flex freely Fig. 6 is asection on the line 6-4; of Fig. 5.

mined l... 18, 1949 2,459,562

UNITED STATES PATENT orrlcs 2,459,562 our WASHER.

Ludger E. La Brle, Detroit, Mich, assignor to Hydraulic Brake Company,Detroit. Mich., a corporation of California Application August 27, 1945,Serial No. 612.944 4 Claims. (Cl. 30933) My invention relates to cupwashers for high ring, all shown in their normal positions withinpressure fluid cylinders such as are used in hythe cylinder. draulicbrake systems for trucks and like ve- Fig. 2 is an elevationof a cupwasher in the hicles. i condition it assumes when not confined in a Cupwashers for hydraulic brake systems are cylinder.

referably made of rubber or some rubber com- Fig. 3 is a section on theline 3-3 through the position because such material is not substancupwasher illustrated in Fig. 2. tially dissolved or softened by brakefluid which Fig. 4 is a section on the line 4-4 through the contains amixture of castor oil and alcohol. It cup washer illustrated in Fig.2.is essential that the rubber of which the cup Fig.5 is amodified form ofcup washer, and

against the cylinder wall so as to not only seal Referring to Fig. 1.the cup washer l is shown against the flow of brake fluid as the pistonmoves circumferentially compressed within a cylinder 8 wipe the cylinderwall substantially clean, leaving piston 9 by a spring H). The movementof the per square inch and when the piston moves fora rectangular groovein the cup washer 1 and is high pressure to flow into the space betweenthe between the ends of the metallic split ring [4 is piston and thecylinder wall, When this hapcovered by an angle member I 5, silversoldered or pens, pieces of rubber are torn loose from the cup therwise,suitably attached to one end of the Washer until eventually the cupwasher is depen r ng 4- stroyed. In Figs. 2, 3 and 4. the cup washer isshown as It is impracticable from a manufacturing provided with a grooveI"! which extends circumstnadpoint to fit the pistons to the cylinderswith 1 p of the cup. such accuracy as to leave no crack into which the eW he being p d th u s W in its In accordance with m invention, th cupcup washer are moved in the non-comprcssion washer is formed with acircumferential, recdirection by the spring l0. tangular cross-sectiongroove around the base he cup Washer lus n Figs; 5 d 6 portion intowhich a split ring of metal is inis of the type usual y sed n WheelCylinders troduced. This ring has a normal size slightly n ather tha inaster compression cylinde s- In against the cylinder throughout theircontacting 4.

split ring is covered by a thin metal angle ata normal size such as tocause the ring to contact tached to one end of the ring to prevent theinthe inner wall of the cylinder when no pressure is trusion of therubber under high pressure applied to the rubber, since there is nonecessity My invention is illustrated in the accompanyno for fluid topass the outside of the ring I under draulic brake master cylinder withits piston, large under pressure of fluid to close the gap beaush rod,cup washer, return spring and split to tween the ring and the cylinderwall.

In operation, the piston 9 is moved toward the right by the movement ofthe push rod l3. After the lip of the cup I has passed the bleed hole2|, brake fluid which occupies the entire space to the right of the cupwasher I is placed under pressure which gradually increases as thepiston 9 is moved further and further to the right. Only a slight amountof required to expand the base of the cup washer I within the ring ll tosuch an extent as to cause the ends 01! the split to enlarge until it ofthe cylinder throughout their entire contacting circumferences. Thisexpansion of the ring takes place long before the pressure of the fluidhas increased to such a degree as would tend to force into the crackbetween the wall. Since the ring I4 is now pressed firmly through itscircumference, no crack or is left into which the rubber of the cupwasher may be squeezed even under very high fluid pressure. The anglemember i5 is made of very thin metal and fits so closely against thering I that the rubber of the'cup washer is not intruded between theangle and the ring. When the spring I0 is permitted to return the piston9 to its normal position more rapidly than the brake fluid can return tothe right end of the cylinder 8, then brake fluid flows from theinterior of the piston 9, through its ducts 22, around the outside orthe now contracted split ring l4, and past the lip of the cup I, theducts l9 and I1 providing.

for the brake fluid even if the rubwasher has become expanded that itnormally fllls the passageways ber of the cup through long use socylinder.

vWhile I have shown and described my invention as applied to hydraulicbraking equipment, it is to be understood that it is not limited thereto. and that it is not to be unduly limited to the exact form of eitherthe ring or the cup washer illustrated in the drawings.

1. In a fluid pressure braking system, a flexible cup Washer having alip of a size greaterthan the diameter of the cylinder in which it is tooperate, a base portion having a normal diameter of less than that ofthe cylinder in which it is to a split ring surrounding a portion theflexible cup Washer and having a normal diameter slightly less than thediameter of the cylinder in which it is to operate, the rubber of thecup washer being suihciently yielding to expand the split ring againstthe cylinder wall under fluid pressure.

2. A cup washer for hydraulic brake master cylinders having acircumferential depression about the periphery of its base, a pistonhaving fluid passages therethrough against which'the cup abuts, and ametallic split ring within the depression in the cup washer having anormal external diameter enough less than the diameter of the cylinderin which the cup washer is to operate to permit a free flow of brakefluid between the ring and the cylinder wall when the pressure in thecup falls below that within the piston.

3. In a fluid pressure braking system, a flexible cup washer having alip of asize greater than the diameter of the cylinder in which it is tooperate, a base portion having a normal diameter of less than that ofthe cylinder in which it is to operate, and a split ring surrounding aportion of the base of the flexible cup washer and having a normaldiameter slightly less of the cylinder in which it is to operate, therubber of the cup washer being sufficiently yielding to expand the splitring against the cylinder wall under fluid pressure and to permit thesplit ring to contract away from the fluid pressure drops belowatmospheric pressure, and an angle plate completely covering two sidesof the ring at the gap between the ends of the ring to prevent rubberfrom being forced into the gap.

4. In a fluid pressure braking system, a flexible cup washer having alip of a size greater than the diameter of the cylinder in which it isto operate, a base portion having a normal diameter of less than that ofthe cylinder in which it is to operate, and a split ring surrounding aportion of the base of the flexible cup washer and having a nornial thediameter of the diameter slightly less than cylinder in which it is tooperate, the rubber or the cup washer being sufllciently yielding toexring against the cylinder wall under fluid pressure and to permit thesplit ring to contract away from the cylinder wall when the fluidpressure drops below atmospheric pressure,

and an angle plate completely covering two sides of the ring at the gapbetween the ends of the ring to prevent rubber from being forced intothe being attached to one end of the ring and the other end of the rinbeing slidable in the angle plate,

LUDGER E. LA BRIE.

REFERENCES CITED The following references are of record in they than thediameter the cylinder wall when

